<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<form action="http://localhost:3000/login" method="post">
  用户名：<input type="text" name="username" />
  密码：<input type="text" name="password" />
  <input type="submit" value="登录">
</form>
</body>
</html>
